Certain patients develop abnormal catabolic states. This arises when the body metabolizes nutrients at a greater rate than the nutrients are supplied to the body, which results in a state of destructive metabolism, also referred to as abnormal metabolism. This state can be induced by illnesses, particularly those illnesses which interfere with normal digestion. Often, this state is caused by surgery which is disruptive of normal metabolism processes. Further, the state can be induced by traumas which induce a necessity for high caloric intake. For example, a burn patient may require as many as 7,000 calories per day due to the damage to the body and the results thereof occasioned by the burn.
With patients having an abnormal catabolic state, it is a constant problem to provide the required nutrients to that patient due to the difficulties encountered as a result of a specific malady or trauma. Very often this difficulty involves the inability of the patient to masticate natural foods or to digest natural foods. Further, in some patients, the use of natural foods produces too much residue for the patient to handle, due to disruptions of the digestive track by way of disease, trauma, or surgery. In the case of burn patients, attempting to simply digest 7,000 calories of natural foods it is an extremely difficult requirement for the patient.
As a result thereof, such patients often suffer severe body weight losses during these abnormal catabolic periods, resulting in severe complications to the primary malady and often resulting in severe body damage or even in death.
To regulate the problems associated with abnormal catabolic states, the art has proposed a variety of procedures. One procedure is that of intravenous feeding, since this route does not require digestion of the nutrients and thereby avoids problems with the digestive tract. While this approach is quite successful, it does have several limitations. Thus, the total volume of liquids which can be induced into the circulatory system is limited, and if attempts are made to over load the volumetric capacity, complications of the lungs and kidneys may well result. For this reason, it is often difficult to supply the required nutrients by venous routes simply by reason of volumetric limitations of the circulatory system. Additionally, it is most dangerous to introduce fats and oils into the blood stream, and intravenous procedures have, of necessity, eliminated fats including such essential fats as linoleic acid. Also, intravenous administered sugars, e.g. dextrose, contain only about half the calories on a weight basis as common fats, and it is difficult to provide sufficiently high caloric value by sustained intravenous feeding when an abnormal catabolic state exists.
To avoid the difficulties with intravenous feeding, a variety of orally ingestible compositions has been proposed. These compositions, generally, are based on the idea of providing a correct balance of protein, or amino acids, fat, carbohydrate, vitamins, and minerals. These systems do enjoy a reasonable success, but they also impose limitations on their use. The systems prepared from some proteins are of extremely high viscosities at high protein levels and, therefore, limit the applicability to those patients who can adequately swallow high viscosity compositions. Additionally, these compositions have utilized protein, protein hydrolysates, or amino acid sources in order to avoid the problem of the digestion of natural foods. The systems prepared from protein hydrolysates or 1-amino acids possess objectionable flavors that make it difficult, and in many cases impossible, for a patient to consume such products other than by tube feeding. Among the sources of nitrogen used are such sources as milk derived proteins, such as milks, casein, and the caseinates; vegetable derived proteins, such as soybean protein, protein hydrolysates, amino acid mixtures and the like. Milks as the source of protein contain high levels of lactose. Because some patients may be lactose intolerant it is desirable that foods of this type be relatively free of lactose. The proteins and protein hydrolysates used, unless supplemented with the proper essential 1-amino acids, may have relatively low Protein Efficiency Ratios. In the cases of some proteins it is difficult to formulate compositions with sufficient nitrogen to provide a high calorie, nutritionally balanced composition, while at the same time avoiding the difficulties of high viscosity. The systems prepared from protein hydrolysates or 1- amino acids possess objectionable flavors. Protein hydrolysates and mixtures of 1-amino acids contain the low molecular weight amino acids. These low molecular weight constituents, in combination with low molecular weight sugars and mineral compounds, used in the formulations, produce in the intestines a high concentration of low molecular weight compounds. As is known, a high concentration of such compounds induces a condition in the intestines where the osmotic pressure across the gut wall increases such that the body expells significant quantities of liquid into the intestines in an effort to wash out the high concentration of low molecular weight compounds. Thus, these compositions with high contents of low molecular weight amino acids, sugars, and salts so increases the osmotic pressure across the gut wall as to produce a condition called "dumping". The possibility of this condition is especially high with patients who require a low residue diet, because of complications in the digestive system. High osmolarity induces diarrhea in the patient as well as other related complications. The problem of high osmolarity is particularly accute in conventional compositions which rely upon protein hydrolysates and 1-amino acid mixtures as the primary nitrogen source, since the amino acids in the protein hydrolysates and 1-amino acid mixtures are of particularly low molecular weight and produce compositions which are particularly prone to induce "dumping".
Accordingly, it would be of distinct advantage in the art to provide compositions which avoid the problem of both intravenous feeding and feeding with conventional ingestible compositions as discussed above.